Dosing & Uses
Dosage Forms & Strengths
tablet
- 400mg
- 800mg
Musculoskeletal Pain
Indicated for acute, painful musculoskeletal conditions
800 mg PO q6-8hr
Dosage Modifications
Renal impairment
- Mild to moderate impairment: Use caution
- Severe impairment: Contraindicated
Hepatic impairment
- Mild to moderate impairment: Use caution
- Severe impairment: Contraindicated
Systemic Sclerosis (Orphan)
Uvadex
In conjunction with the UVAR photopheresis to treat diffuse systemic sclerosis
Orphan indication sponsor
- Therakos, Inc; Oaklands Corporate Center; 437 Creamery Way; Exton, PA 19341
Cardiac Allograft Rejection (Orphan)
Uvadex
Prevention of acute rejection of cardiac allografts
Orphan indication sponsor
- Therakos, Inc; Oaklands Corporate Center; 437 Creamery Way; Exton, PA 19341
Dosage Forms and Strengths
tablet
- 400mg
- 800mg
Musculoskeletal Pain
<12 years: Safety and efficacy not established
≥12 years: 800 mg PO q6-8hr
Systemic Sclerosis (Orphan)
Uvadex
In conjunction with the UVAR photopheresis to treat diffuse systemic sclerosis
Orphan indication sponsor
- Therakos, Inc; Oaklands Corporate Center; 437 Creamery Way; Exton, PA 19341
Cardiac Allograft Rejection (Orphan)
Uvadex
Prevention of acute rejection of cardiac allografts
Orphan indication sponsor
- Therakos, Inc; Oaklands Corporate Center; 437 Creamery Way; Exton, PA 19341
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (17)
- apalutamide
apalutamide will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.
- benzhydrocodone/acetaminophen
benzhydrocodone/acetaminophen, metaxalone. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
benzhydrocodone/acetaminophen and metaxalone both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate - buprenorphine subdermal implant
buprenorphine subdermal implant and metaxalone both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- buprenorphine transdermal
buprenorphine transdermal and metaxalone both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- buprenorphine, long-acting injection
buprenorphine, long-acting injection and metaxalone both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- calcium/magnesium/potassium/sodium oxybates
metaxalone, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- fexinidazole
fexinidazole will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.
- hydrocodone
hydrocodone, metaxalone. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- idelalisib
idelalisib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates
- ivosidenib
ivosidenib will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.
- lopinavir
lopinavir will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- metoclopramide intranasal
metaxalone, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
- olopatadine intranasal
metaxalone and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- sodium oxybate
metaxalone, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- sufentanil SL
sufentanil SL, metaxalone. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- tucatinib
tucatinib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.
- voxelotor
voxelotor will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.
Monitor Closely (183)
- abiraterone
abiraterone increases levels of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.
- abobotulinumtoxinA
metaxalone increases effects of abobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
- acrivastine
acrivastine and metaxalone both increase sedation. Use Caution/Monitor.
- alfentanil
metaxalone and alfentanil both increase sedation. Use Caution/Monitor.
- alprazolam
alprazolam and metaxalone both increase sedation. Use Caution/Monitor.
- amisulpride
amisulpride and metaxalone both increase sedation. Use Caution/Monitor.
- amitriptyline
metaxalone and amitriptyline both increase sedation. Use Caution/Monitor.
- amobarbital
amobarbital and metaxalone both increase sedation. Use Caution/Monitor.
amobarbital will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - amoxapine
metaxalone and amoxapine both increase sedation. Use Caution/Monitor.
- apomorphine
metaxalone and apomorphine both increase sedation. Use Caution/Monitor.
- aripiprazole
metaxalone and aripiprazole both increase sedation. Use Caution/Monitor.
- asenapine
asenapine and metaxalone both increase sedation. Use Caution/Monitor.
- asenapine transdermal
asenapine transdermal and metaxalone both increase sedation. Use Caution/Monitor.
- avapritinib
avapritinib and metaxalone both increase sedation. Use Caution/Monitor.
- azelastine
azelastine and metaxalone both increase sedation. Use Caution/Monitor.
- baclofen
baclofen and metaxalone both increase sedation. Use Caution/Monitor.
- belladonna and opium
metaxalone and belladonna and opium both increase sedation. Use Caution/Monitor.
- benperidol
metaxalone and benperidol both increase sedation. Use Caution/Monitor.
- benzphetamine
metaxalone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- brexanolone
brexanolone, metaxalone. Either increases toxicity of the other by sedation. Use Caution/Monitor.
- brexpiprazole
brexpiprazole and metaxalone both increase sedation. Use Caution/Monitor.
- brimonidine
brimonidine and metaxalone both increase sedation. Use Caution/Monitor.
- brivaracetam
brivaracetam and metaxalone both increase sedation. Use Caution/Monitor.
- brompheniramine
brompheniramine and metaxalone both increase sedation. Use Caution/Monitor.
- buprenorphine
metaxalone and buprenorphine both increase sedation. Use Caution/Monitor.
- buprenorphine buccal
metaxalone and buprenorphine buccal both increase sedation. Use Caution/Monitor.
- buprenorphine, long-acting injection
buprenorphine, long-acting injection increases effects of metaxalone by Other (see comment). Modify Therapy/Monitor Closely. Comment: Buprenorphine may enhance the neuromuscular blocking action of skeletal muscle relaxants and increase risk for respiratory depression. Monitor for signs of respiratory depression that may be greater than otherwise expected and decrease muscle relaxant dosage as necessary.
- butabarbital
butabarbital and metaxalone both increase sedation. Use Caution/Monitor.
- butalbital
butalbital and metaxalone both increase sedation. Use Caution/Monitor.
- butorphanol
metaxalone and butorphanol both increase sedation. Use Caution/Monitor.
- cannabidiol
cannabidiol, metaxalone. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.
- carbinoxamine
carbinoxamine and metaxalone both increase sedation. Use Caution/Monitor.
- carisoprodol
carisoprodol and metaxalone both increase sedation. Use Caution/Monitor.
- cenobamate
cenobamate will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
- chloral hydrate
chloral hydrate and metaxalone both increase sedation. Use Caution/Monitor.
- chlordiazepoxide
chlordiazepoxide and metaxalone both increase sedation. Use Caution/Monitor.
- chlorpheniramine
chlorpheniramine and metaxalone both increase sedation. Use Caution/Monitor.
- chlorpromazine
metaxalone and chlorpromazine both increase sedation. Use Caution/Monitor.
- chlorzoxazone
chlorzoxazone and metaxalone both increase sedation. Use Caution/Monitor.
- cinnarizine
cinnarizine and metaxalone both increase sedation. Use Caution/Monitor.
- clemastine
clemastine and metaxalone both increase sedation. Use Caution/Monitor.
- clobazam
metaxalone, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
- clomipramine
metaxalone and clomipramine both increase sedation. Use Caution/Monitor.
- clonazepam
clonazepam and metaxalone both increase sedation. Use Caution/Monitor.
- clorazepate
clorazepate and metaxalone both increase sedation. Use Caution/Monitor.
- clozapine
metaxalone and clozapine both increase sedation. Use Caution/Monitor.
- codeine
metaxalone and codeine both increase sedation. Use Caution/Monitor.
- crofelemer
crofelemer increases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.
- cyclizine
cyclizine and metaxalone both increase sedation. Use Caution/Monitor.
- cyclobenzaprine
cyclobenzaprine and metaxalone both increase sedation. Use Caution/Monitor.
- cyproheptadine
cyproheptadine and metaxalone both increase sedation. Use Caution/Monitor.
- dabrafenib
dabrafenib will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
- dantrolene
dantrolene and metaxalone both increase sedation. Use Caution/Monitor.
- daridorexant
metaxalone and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- desipramine
metaxalone and desipramine both increase sedation. Use Caution/Monitor.
- dexchlorpheniramine
dexchlorpheniramine and metaxalone both increase sedation. Use Caution/Monitor.
- dexfenfluramine
metaxalone increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexmedetomidine
dexmedetomidine and metaxalone both increase sedation. Use Caution/Monitor.
- dextromoramide
metaxalone and dextromoramide both increase sedation. Use Caution/Monitor.
- diamorphine
metaxalone and diamorphine both increase sedation. Use Caution/Monitor.
- diazepam
diazepam and metaxalone both increase sedation. Use Caution/Monitor.
- diazepam intranasal
diazepam intranasal, metaxalone. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.
- difelikefalin
difelikefalin and metaxalone both increase sedation. Use Caution/Monitor.
- difenoxin hcl
metaxalone and difenoxin hcl both increase sedation. Use Caution/Monitor.
- dimenhydrinate
dimenhydrinate and metaxalone both increase sedation. Use Caution/Monitor.
- diphenhydramine
diphenhydramine and metaxalone both increase sedation. Use Caution/Monitor.
- diphenoxylate hcl
metaxalone and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
- dipipanone
metaxalone and dipipanone both increase sedation. Use Caution/Monitor.
- dopexamine
metaxalone increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dosulepin
metaxalone and dosulepin both increase sedation. Use Caution/Monitor.
- doxepin
metaxalone and doxepin both increase sedation. Use Caution/Monitor.
- doxylamine
doxylamine and metaxalone both increase sedation. Use Caution/Monitor.
- droperidol
metaxalone and droperidol both increase sedation. Use Caution/Monitor.
- efavirenz
efavirenz will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- elagolix
elagolix decreases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events. - encorafenib
encorafenib, metaxalone. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.
- esketamine intranasal
esketamine intranasal, metaxalone. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
- estazolam
estazolam and metaxalone both increase sedation. Use Caution/Monitor.
- ethanol
metaxalone and ethanol both increase sedation. Use Caution/Monitor.
- etomidate
etomidate and metaxalone both increase sedation. Use Caution/Monitor.
- fedratinib
fedratinib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
- fenfluramine
metaxalone increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- fluphenazine
metaxalone and fluphenazine both increase sedation. Use Caution/Monitor.
- flurazepam
flurazepam and metaxalone both increase sedation. Use Caution/Monitor.
- ganaxolone
metaxalone and ganaxolone both increase sedation. Use Caution/Monitor.
- haloperidol
metaxalone and haloperidol both increase sedation. Use Caution/Monitor.
- hydromorphone
metaxalone and hydromorphone both increase sedation. Use Caution/Monitor.
- hydroxyzine
hydroxyzine and metaxalone both increase sedation. Use Caution/Monitor.
- iloperidone
metaxalone and iloperidone both increase sedation. Use Caution/Monitor.
iloperidone increases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4. - imipramine
metaxalone and imipramine both increase sedation. Use Caution/Monitor.
- incobotulinumtoxinA
metaxalone, incobotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
- istradefylline
istradefylline will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
- ketamine
ketamine and metaxalone both increase sedation. Use Caution/Monitor.
- ketotifen, ophthalmic
metaxalone and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- lasmiditan
lasmiditan, metaxalone. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.
- lemborexant
lemborexant, metaxalone. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.
- lenacapavir
lenacapavir will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.
- levorphanol
metaxalone and levorphanol both increase sedation. Use Caution/Monitor.
- lofepramine
metaxalone and lofepramine both increase sedation. Use Caution/Monitor.
- lofexidine
metaxalone and lofexidine both increase sedation. Use Caution/Monitor.
- loprazolam
loprazolam and metaxalone both increase sedation. Use Caution/Monitor.
- lorazepam
lorazepam and metaxalone both increase sedation. Use Caution/Monitor.
- lorcaserin
lorcaserin will increase the level or effect of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- lormetazepam
lormetazepam and metaxalone both increase sedation. Use Caution/Monitor.
- loxapine
metaxalone and loxapine both increase sedation. Use Caution/Monitor.
- loxapine inhaled
metaxalone and loxapine inhaled both increase sedation. Use Caution/Monitor.
- lurasidone
lurasidone, metaxalone. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.
- maprotiline
metaxalone and maprotiline both increase sedation. Use Caution/Monitor.
- marijuana
metaxalone and marijuana both increase sedation. Use Caution/Monitor.
- melatonin
metaxalone and melatonin both increase sedation. Use Caution/Monitor.
- meperidine
metaxalone and meperidine both increase sedation. Use Caution/Monitor.
- meprobamate
metaxalone and meprobamate both increase sedation. Use Caution/Monitor.
- methadone
metaxalone and methadone both increase sedation. Use Caution/Monitor.
- methocarbamol
metaxalone and methocarbamol both increase sedation. Use Caution/Monitor.
- methylenedioxymethamphetamine
metaxalone increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- midazolam
midazolam and metaxalone both increase sedation. Use Caution/Monitor.
- midodrine
metaxalone increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- mifepristone
mifepristone will increase the level or effect of metaxalone by Other (see comment). Use Caution/Monitor. Inhibits CYP2C8/2C9; use smallest recommended doses for substrates and monitor
- mirabegron
mirabegron will increase the level or effect of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- mirtazapine
metaxalone and mirtazapine both increase sedation. Use Caution/Monitor.
- mitotane
mitotane decreases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.
- morphine
metaxalone and morphine both increase sedation. Use Caution/Monitor.
- motherwort
metaxalone and motherwort both increase sedation. Use Caution/Monitor.
- moxonidine
metaxalone and moxonidine both increase sedation. Use Caution/Monitor.
- nabilone
metaxalone and nabilone both increase sedation. Use Caution/Monitor.
- nalbuphine
metaxalone and nalbuphine both increase sedation. Use Caution/Monitor.
- nefazodone
nefazodone will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nortriptyline
metaxalone and nortriptyline both increase sedation. Use Caution/Monitor.
- olanzapine
metaxalone and olanzapine both increase sedation. Use Caution/Monitor.
- oliceridine
oliceridine, metaxalone. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
metaxalone increases toxicity of oliceridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor for signs of urinary retention or reduced gastric motility if oliceridine is coadministered with anticholinergics. - opium tincture
metaxalone and opium tincture both increase sedation. Use Caution/Monitor.
- orphenadrine
metaxalone and orphenadrine both increase sedation. Use Caution/Monitor.
- oxazepam
oxazepam and metaxalone both increase sedation. Use Caution/Monitor.
- oxycodone
metaxalone and oxycodone both increase sedation. Use Caution/Monitor.
- oxymorphone
metaxalone and oxymorphone both increase sedation. Use Caution/Monitor.
- paliperidone
metaxalone and paliperidone both increase sedation. Use Caution/Monitor.
- papaveretum
metaxalone and papaveretum both increase sedation. Use Caution/Monitor.
- papaverine
metaxalone and papaverine both increase sedation. Use Caution/Monitor.
- pentazocine
metaxalone and pentazocine both increase sedation. Use Caution/Monitor.
- pentobarbital
pentobarbital and metaxalone both increase sedation. Use Caution/Monitor.
- perphenazine
metaxalone and perphenazine both increase sedation. Use Caution/Monitor.
- phenobarbital
phenobarbital and metaxalone both increase sedation. Use Caution/Monitor.
- phenylephrine PO
metaxalone increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- pholcodine
metaxalone and pholcodine both increase sedation. Use Caution/Monitor.
- pimozide
metaxalone and pimozide both increase sedation. Use Caution/Monitor.
- prabotulinumtoxinA
metaxalone increases effects of prabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
- primidone
primidone and metaxalone both increase sedation. Use Caution/Monitor.
- prochlorperazine
metaxalone and prochlorperazine both increase sedation. Use Caution/Monitor.
- promethazine
promethazine and metaxalone both increase sedation. Use Caution/Monitor.
- propofol
propofol and metaxalone both increase sedation. Use Caution/Monitor.
- propylhexedrine
metaxalone increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- protriptyline
metaxalone and protriptyline both increase sedation. Use Caution/Monitor.
- quazepam
quazepam and metaxalone both increase sedation. Use Caution/Monitor.
- quetiapine
metaxalone and quetiapine both increase sedation. Use Caution/Monitor.
- ramelteon
metaxalone and ramelteon both increase sedation. Use Caution/Monitor.
- remifentanil
metaxalone increases effects of remifentanil by pharmacodynamic synergism. Modify Therapy/Monitor Closely. CNS depressant effect increased.
- remimazolam
remimazolam, metaxalone. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.
- risperidone
metaxalone and risperidone both increase sedation. Use Caution/Monitor.
- rucaparib
rucaparib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.
- scullcap
metaxalone and scullcap both increase sedation. Use Caution/Monitor.
- secobarbital
secobarbital and metaxalone both increase sedation. Use Caution/Monitor.
- shepherd's purse
metaxalone and shepherd's purse both increase sedation. Use Caution/Monitor.
- stiripentol
stiripentol, metaxalone. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
stiripentol, metaxalone. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence. - sufentanil
metaxalone and sufentanil both increase sedation. Use Caution/Monitor.
- tapentadol
metaxalone and tapentadol both increase sedation. Use Caution/Monitor.
- tazemetostat
tazemetostat will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tecovirimat
tecovirimat will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.
- temazepam
temazepam and metaxalone both increase sedation. Use Caution/Monitor.
- teriflunomide
teriflunomide increases levels of metaxalone by Other (see comment). Use Caution/Monitor. Comment: Teriflunomide inhibits CYP2C8; caution when coadministered with CYP2C8 substrates.
teriflunomide decreases levels of metaxalone by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. - thioridazine
metaxalone and thioridazine both increase sedation. Use Caution/Monitor.
- thiothixene
metaxalone and thiothixene both increase sedation. Use Caution/Monitor.
- topiramate
metaxalone and topiramate both increase sedation. Modify Therapy/Monitor Closely.
- tramadol
metaxalone and tramadol both increase sedation. Use Caution/Monitor.
- trazodone
metaxalone and trazodone both increase sedation. Use Caution/Monitor.
- triazolam
triazolam and metaxalone both increase sedation. Use Caution/Monitor.
- triclofos
triclofos and metaxalone both increase sedation. Use Caution/Monitor.
- trifluoperazine
metaxalone and trifluoperazine both increase sedation. Use Caution/Monitor.
- trimipramine
metaxalone and trimipramine both increase sedation. Use Caution/Monitor.
- xylometazoline
metaxalone increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ziconotide
metaxalone and ziconotide both increase sedation. Use Caution/Monitor.
- ziprasidone
metaxalone and ziprasidone both increase sedation. Use Caution/Monitor.
- zotepine
metaxalone and zotepine both increase sedation. Use Caution/Monitor.
Minor (8)
- acetazolamide
acetazolamide will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- anastrozole
anastrozole will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- cyclophosphamide
cyclophosphamide will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- eucalyptus
metaxalone and eucalyptus both increase sedation. Minor/Significance Unknown.
- larotrectinib
larotrectinib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- levoketoconazole
levoketoconazole will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ribociclib
ribociclib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sage
metaxalone and sage both increase sedation. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Drug-induced gastrointestinal disturbance
Nausea
Vomiting
Dizziness
Headache
Somnolence
Nervousness
Hemolytic anemia (rare)
Leukopenia (rare)
Jaundice (rare)
Immune hypersensitivity reaction (rare)
Postmarketing Report
Serotonin syndrome (when used concomitantly with serotonergic drugs or doses higher than recommended)
Warnings
Contraindications
Hypersensitivity
History of drug-induced hemolytic anemia
Significant renal/hepatic impairment
Cautions
CNS depression may occur
Sedative effects may be potentiated when used with other sedatives
Medication is poorly tolerated by the elderly
Bioavailability may increase in female patients
Use caution in renal and hepatic impairment
Safety and efficacy not established in children <12 years
May impair physical or mental abilities; caution patient against operating heavy machinery or performing tasks requiring mental alertness
Serotonin syndrome
- Cases of serotonin syndrome, a potentially life-threatening condition, reported during concomitant use of serotonergic drugs with this drug when used within recommended dosage range and with metaxalone as a single agent taken at doses higher than recommended dose (see drug interaction overview)
- Serotonin syndrome symptoms may include mental status changes (eg, agitation, hallucinations, coma), autonomic instability (eg, tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (eg, hyperreflexia, incoordination, rigidity), and/or gastrointestinal symptoms (eg, nausea, vomiting, diarrhea); the onset of symptoms generally occurs within several hours to a few days, but may occur later than that
- Discontinue therapy if serotonin syndrome suspected
Drug interaction overview
- Sedative effects of this drug and other CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants) may be additive; caution should be exercised with patients who take more than one of these CNS depressants simultaneously
- Serotonin syndrome have occurred with concomitant use of serotonergic drugs, including selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, opioids (particularly fentanyl, meperidine, and methadone), drugs that affect the serotonergic neurotransmitter system (eg, mirtazapine, trazodone, tramadol), and drugs that impair metabolism of serotonin (including monoamine oxidase (MAO) inhibitors, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue)
Pregnancy & Lactation
Pregnancy category: C
Lactation: Unknown if excreted in breast milk; not recommended
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
General CNS depression; no direct effect on skeletal muscle; may disrupt the spasm-pain-spasm cycle; does not havae direct effect on skeletal muscle
Absorption
Onset: Within 1 hr
Duration: 4-6 hr
Peak plasma time: 3 hr
Peak plasma concentration: 296 mcg/mL
Distribution
Vd: 800 L
Metabolism
Liver
Metabolites: Unidentified
Elimination
Half-life elimination: 4-14 hr
Excretion: Urine
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
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metaxalone oral - | 800 mg tablet | ![]() | |
metaxalone oral - | 800 mg tablet | ![]() | |
metaxalone oral - | 800 mg tablet | ![]() | |
metaxalone oral - | 400 mg tablet | ![]() | |
metaxalone oral - | 800 mg tablet | ![]() | |
metaxalone oral - | 800 mg tablet | ![]() | |
metaxalone oral - | 400 mg tablet | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
metaxalone oral
METAXALONE - ORAL
(me-TAX-a-lone)
COMMON BRAND NAME(S): Skelaxin
USES: Metaxalone is used to treat muscle spasms/pain. It is usually used along with rest, physical therapy, and other treatment.
HOW TO USE: Take this medication by mouth with or without food as directed by your doctor. Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase. If you take this medication after a high-fat meal and experience side effects, it may be best to take this drug on an empty stomach or after a light meal.The dosage is based on your medical condition and response to treatment.To prevent a very serious high blood pressure reaction, it is very important that you follow a special diet recommended by your doctor or dietician to limit your intake of tyramine while you are taking this medicine. Avoid foods and beverages that are high in tyramine, including aged cheeses, dried/aged meats and sausages (such as salami, liverwurst), preserved fish (such as pickled herring), products that contain large amounts of yeast (such as bouillon cubes, powdered soup/gravy, homemade or sourdough bread), fermented foods (such as sauerkraut, kim chee), most soybean products (such as soy sauce, tofu), broad/fava beans, red wine, sherry, tap beers, and vermouth. Consult your doctor or dietician for more details and a complete list of other foods that contain tyramine which you should limit or avoid.Tell your doctor if your condition does not improve or if it worsens.
SIDE EFFECTS: Drowsiness, dizziness, nausea, vomiting, and upset stomach may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as nervousness, irritability, confusion), signs of infection (such as sore throat that doesn't go away, fever), yellowing eyes/skin, unusual tiredness, dark urine.This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.This drug may rarely cause an attack of extremely high blood pressure (hypertensive crisis), which may be fatal. Many drug and food interactions can increase this risk (see How to Use and Drug Interactions sections). Get medical help right away if any of these serious side effects occur: severe headache, fast/slow/irregular/pounding heartbeat, chest pain, neck stiffness/soreness, severe nausea/vomiting, sweating/clammy skin (sometimes with fever), widened pupils, vision changes (such as double/blurred vision), sudden sensitivity to light (photophobia).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking metaxalone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, anemia, seizures.This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug, especially dizziness, drowsiness, or confusion. These side effects can increase the risk of falling.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: See also How to Use section.Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: diet pills/appetite suppressants (such as diethylpropion), drugs for attention deficit disorder (such as atomoxetine, methylphenidate), apraclonidine, bupropion, buspirone, carbamazepine, cyclobenzaprine, deutetrabenazine, a certain combination product (dextromethorphan/quinidine), levodopa, maprotiline, methyldopa, metoclopramide, certain opioid pain relievers (such as fentanyl, meperidine, methadone, tapentadol), certain drugs for Parkinson's disease (such as entacapone, tolcapone), certain supplements (such as tryptophan, tyramine), tetrabenazine, tricyclic antidepressants (such as amitriptyline, doxepin), valbenazine.The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including mirtazapine, SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), tramadol, certain "triptans" used to treat migraine headaches (such as rizatriptan, sumatriptan, zolmitriptan), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.Some products can interact with metaxalone if you take them together, or even if you take them weeks before or after taking metaxalone. Tell your doctor or pharmacist if you take anything in the list of products that may interact with this drug, or any of the products that increase serotonin, within 2 weeks before or after taking metaxalone. Also tell them if you have taken fluoxetine within 5 weeks before starting metaxalone. Ask your doctor how much time to wait between starting or stopping any of these drugs and starting metaxalone.Taking other MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Do not take any other MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and after treatment with this medication. Ask your doctor when to start or stop taking this medication.Before using metaxalone, report the use of drugs that may increase the risk of extremely high blood pressure (hypertensive crisis) when combined with metaxalone, including herbal products (such as ephedra/ma huang), nasal decongestants (such as phenylephrine, pseudoephedrine), and stimulants (such as amphetamines, ephedrine, epinephrine, phenylalanine). Metaxalone should not be used with any of these medications. Talk to your doctor or pharmacist for more details.Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), other muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.This medication may interfere with certain lab tests (such as certain urine glucose tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe drowsiness.
NOTES: Do not share this medication with others.This medication has been prescribed for your current condition only. Do not use it later for another condition unless your doctor directs you to do so. A different medication may be necessary in that case.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised May 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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Adding plans allows you to:
- View the formulary and any restrictions for each plan.
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